JP3358983B2 - Circuit breaker and its voltage trip device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit breaker having a contact for opening and closing an electric circuit and an opening and closing mechanism for opening and closing the contact in an insulating housing. The present invention relates to a drive device that is operated and used, and a voltage trip device of a circuit breaker that enables a remote opening / closing operation.

[0002]

2. Description of the Related Art Conventionally, various circuit breakers for supplying power from a power supply to a load and cutting and protecting an electric circuit due to an overload or a short circuit have been known. Such a circuit breaker is disclosed in, for example, Japanese Patent Publication No.
As is known from, for example, US Pat.
An overload current that detects the overload current or short-circuit current flowing through the circuit breaker is housed in a case formed of an insulating member, with the contacts that open and close the electric circuit and the switching mechanism that opens and closes the contacts. A detection device is provided.

By the way, in such a circuit breaker, a contact is cut off in accordance with detection of an overload current, a short-circuit current or the like. At that time, an opening / closing mechanism for opening / closing the contact is stored in an insulating casing. This opening / closing mechanism is operated by an operating device. Alternatively, a voltage trip device, which is an attached device, is stored in a part of the circuit breaker, and the switching mechanism is operated by using the voltage trip device from a remote place, thereby breaking the contact. ing. As these operating devices, for example, devices using electromagnetic force generated by exciting coils, such as electromagnetic plungers, are widely used.

[0004]

As described above, the actuating device and the voltage trip device in the circuit breaker known from the prior art are generally provided by an electromagnetic device such as an electromagnetic plunger as described above. It is configured. In such an electromagnetic actuator, generally, a movable core is slidably provided inside an electromagnetic coil provided in a yoke portion made of a ferromagnetic material, and when an exciting current is supplied to this electromagnetic coil, The movable core is attracted by the generated magnetic force. Then, the operating portion of the opening / closing mechanism is moved by the suction of the movable core to perform a contact breaking operation.

[0005] Further, the actuating devices and voltage trip devices in such circuit breakers are generally not used frequently and are not used frequently. However, due to its intended use, when this was activated,
Despite the effects of aging, the desired operation is ensured,
That is, it is required that the contact switching mechanism in the circuit breaker be operated reliably.

However, the above-described conventional circuit breaker and the voltage trip device which is an auxiliary device thereof are not always sufficiently designed from this point of view. Therefore, the circuit breaker is particularly formed inside the bobbin of the electromagnetic coil. The movable core slidably provided in the groove does not slide,
There is a problem that a desired opening / closing operation is not performed.

That is, as described above, when the movable core is operated by being attracted to the movable portion by the electromagnetic coil, the movable core that is attracted and slid by the generated electromagnetic force comes into contact with the operating portion of the opening / closing mechanism. When the movable core is moved, a kind of rotational torque or the like is generated in the movable core together with the reaction force of the return spring. For this reason, a part of the movable core may have a one-sided contact in the slide groove, so that a desired suction operation may not be achieved.

In view of the above-mentioned problems in the prior art, the present invention provides a contact opening / closing mechanism in a circuit breaker without causing any trouble in the suction operation due to the above-mentioned contact of the movable core. It is an object of the present invention to provide a reliable circuit breaker and its voltage trip device that can operate.

[0009]

That is, in order to achieve the above object, first, the present invention provides:
By opening / closing operation of an electric circuit by an operation handle, a mechanism unit housed in an insulating case is operated to open and close at least a pair of contacts housed in the insulating case, and an overcurrent exceeding a rated current is detected to detect the overcurrent. A circuit breaker for disconnecting the pair of contacts by a mechanism, wherein the insulating case further includes an operating unit for operating the mechanism, and the operating unit moves the operating unit. The electromagnetic actuating means comprises a yoke portion, a movable core slidably provided inside an electromagnetic coil provided in the yoke portion, and a part of the movable core. Attaching the return spring directly ,
Direction part contact portion between the actuation portion is formed on, and the position <br/> acting the suction force exerted by the electromagnetic force against the movable core, that the suction force at the movable core acts To
A circuit breaker arranged to act at a position substantially intermediate between a position where a return force of the return spring acts and a position where a reaction force from the operating portion acts in a direction perpendicular to the direction. .

Further, according to the present invention, in a circuit breaker as described in the above, further, the suction force, the return to the return force of the spring and acts in the opposite direction, against the movable core The suction force exerted by the electromagnetic force is substantially at an intermediate point on a line connecting a position where the return spring abuts against the movable core to apply a return force and a position where the return spring abuts on the operating portion and a reaction force is applied. It is arranged to work in the position.

Further, according to the present invention, in order to achieve the above-mentioned object, at least one pair of at least one pair of housings housed in the insulating case is operated by opening / closing an electric path by an operating handle to operate the mechanism housed in the insulating case. It opens and closes the contact, and a part of the circuit breaker to cut the pair of contacts by the mechanism to detect or overcurrent rated current
Are store, a voltage trip device for a circuit is cut off by operating the remotely by driving the operating portion of the mechanism section disposed in the insulating casing of the circuit breaker, and the yoke portion, wherein A movable core is slidably provided inside an electromagnetic coil provided in the yoke part, and a return spring is directly attached to a part of the movable core, and a contact part with the operating part is formed in a part thereof, and attracting force exerted by the electromagnetic force against the movable core, the suction in the movable core
In a direction perpendicular to the direction in which the force acts, it is disposed so as to act at a substantially intermediate position between the position where the return force of the return spring acts and the position where the reaction force from the operating portion acts. Circuit breaker voltage trip device is provided.

Further, according to the present invention, in the voltage release device for a circuit breaker described above, the suction force acts in a direction opposite to a return force by the return spring, and the movable core for that exerted by the electromagnetic force, the line connecting the position where the return spring against the movable core exerts a return force in contact, and a position in which the actuating portion and the contact with the reaction force acts , Are arranged to work at approximately intermediate positions.

[0013]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

First, FIG. 4 shows a cross section of a circuit breaker according to an embodiment of the present invention. In the figure, for example, a heat-resistant thermoplastic resin insulator or the like is formed into a predetermined shape. A power supply side terminal 11A and a load side terminal 17A are provided in a molded case 6 including a bottom case 61 and a front cover 62 formed as described above. Inside the molded case 6, the main circuit case 2 is provided. Installed. Inside the main circuit case 2, there are provided a power-side fixed contact stand 11, a power-side fixed contact 12, a power-side movable contact 13, a movable contact base 14, a load-side movable contact 15, and a load-side fixed contact 1.
6. The main circuit unit 20 is constituted by the load-side fixed contact block 17, the arc extinguishing device 30 called an arc chute, and the like. Also, reference numeral 22 in the figure will be described later,
The holding member 22 holds the movable contact stand 14. The holding member 22 is urged in the counterclockwise direction by the action of a spring 22D, and the pressure at the time of contact between the contacts is set to a predetermined value by the spring 22D.

An open / close operation handle 41 protruding outside the case is provided above the main circuit case 2 and includes a trip lever 3A, a trip member (latch) 3B, a hook 4, a link mechanism 26, and the like. The opening / closing mechanism unit 3 is provided. Further, a tripping mechanism 5 including a stationary core 51, a movable core 52, and a transmission lever 53 is provided, and the transmission lever 53 of the tripping mechanism is provided.
Transmits the operation of the movable core 52 to the opening / closing mechanism unit 3. Reference numeral 3P in the figure is an operation pin of a tripping mechanism which constitutes a part of the feature of the present invention, which will be described in detail later. By moving the operation pin 3P to the left in the figure, The trip mechanism 5 is operated to cut off the circuit. Further, reference numeral 55 denotes a current transformer (hereinafter, “C”) for detecting an overcurrent of the main circuit.
T "), and reference numeral 57 denotes a circuit board forming a signal processing device for detecting the overcurrent using an electronic circuit.

A top view and an external perspective view of the circuit breaker are shown in FIGS. As is clear from FIG. 5, this circuit breaker is a so-called three-phase circuit breaker, and the main circuit for each phase is provided inside the molded case 6. In the embodiment, three poles are provided in parallel. In actual installation, the power supply side is fixed upward, and the load side is fixed downward, for example, on a mounting board. Further, in FIG. 6, reference numeral 70 denotes a slide cover for storing and closing an accessory device inside the mold case 6.

Further, FIG. 8 shows the internal details of the opening / closing mechanism unit 3 including the main circuit unit mounted inside the main circuit case 2 and the operation handle 41. Reference numerals indicate the same components as described above. In this figure, reference numeral 22 denotes a substantially cylindrical holding member 22 for opening and closing the three-phase movable contacts 13 and 15 attached to the movable contact base 14 constituting the main circuit substantially simultaneously. And the end face is "ten"
A letter-shaped projection 22A is formed. Reference numeral 24 in the figure denotes a connecting portion for connecting the holding members 22 to each other. The connecting portion 24 includes an arm portion 24A and a "cross-shaped" convex portion 22A corresponding to the "cross-shaped" convex portion 22A. A cross-shaped concave portion or hole 24B and an engaging portion 24C are formed.
The engaging portion 24C is engaged with the engaging portion 26A of the link mechanism 26.

FIG. 7 is an exploded view showing a holding member 22 for holding a movable contact stand 14 to which the three-phase movable contacts 13 and 15 constituting the main circuit are attached,
The relationship with the connecting portion 24 inserted and arranged between the two is shown. As is apparent from this figure, these three holding members 22 are connected to each other by the connecting portion 24, whereby the three-phase moving contacts 13, 15 open and close substantially simultaneously.

FIG. 9 is an exploded view showing details of a main circuit unit 20 housed in the main circuit case 2 composed of a pair of insulating resin cases. That is, it is composed of a holding member 22 for holding the movable contact stand 14, a power supply-side fixed contact stand 11, a load-side fixed contact stand 17, an arc extinguishing device 30, and the like. Further, the main circuit case 2 is provided with an outlet for discharging a high-temperature, high-pressure arc gas generated inside the main circuit case 2 when the electric circuit is cut off.
An outlet 2A on the power supply side contact side and a load side outlet 2B are formed. A plurality of (three in the present embodiment) main circuit cases 2 accommodating the main circuit units 20 are arranged in parallel in the mold case 6 as shown in FIG. I have.

In the circuit breaker configured as described above,
First, the opening / closing operation handle 41 is turned on / off (ON-
An OFF) operation causes a toggle link mechanism included in the opening / closing mechanism unit 3 to operate, and by this rotation, the holding member 22 connected to this mechanism rotates in the counterclockwise direction in FIG. Movable contact stand 14 held
To rotate the power supply side fixed contact 12 and the power supply side movable contact 13,
Close the load-side movable contact 15 and the load-side fixed contact 16 (ON)
Then, the holding member 22 is rotated clockwise in the drawing to open (OFF) the space between the contacts.

On the other hand, the overcurrent in the circuit breaker is detected by the CT 55 which is disposed substantially in the middle of the fixed contact stand 17 on the load side inside the molded case 6 and includes a core portion and a coil portion. The signal detected by the CT 55 is confirmed by a circuit board 57 forming a signal processing device based on the output voltage, and although not shown, the operation of the movable core by the output coil causes the opening / closing mechanism unit 3 to operate. The trip operation is performed to cut off the current supply path.

In the case of a short circuit, for example,
An excessive current exceeding 0 times occurs. In such a case, in the main circuit unit 20, the excessive current flows from the power supply side terminal 11A, passes through the power supply side fixed contact stand 11, passes through the power supply side fixed contact 12, and the power supply side movable contact 1
3, the load-side terminal 1 via the movable contact stand 14, the load-side movable contact 15, the load-side fixed contact 16, and the load-side fixed contact base 17
Flows to 7A. When such an excessive current flows, an electromagnetic repulsive force is generated due to current concentration or the like at the contact portion, whereby the fixed contacts 12, 15 and the movable contacts 13, 16 repel and separate. Thereafter, as in the case of the occurrence of the overcurrent, the C
The arc current is detected by T55 and confirmed by the circuit board 57 forming the signal processing device, and the movable core is operated by the output coil to trip the opening / closing mechanism unit 3 to cut off the current supply path. This is the same as above.

In the circuit breaker, the circuit is cut off by operating the trip lever 41 or when the above-mentioned short circuit or overcurrent occurs, that is, the holding member 22 is rotated. Movable contact 13, 1
It is required not only to disconnect the fixed contacts 5 from the fixed contacts 12 and 15 but also to electrically trip the circuit breaker from a distance. In response to such a request, an additional device called a voltage trip device (SHT) is additionally attached, and the circuit breaker is tripped via the voltage trip device.

The voltage trip device 80 is shown in FIG.
As shown in the figure, the slide cover 70 slidably attached to a part of the surface of the front cover 62 of the mold case 6 which is the insulating case of the circuit breaker is opened, and is stored in the recess formed therein. Attach it. The operation pin 3P of the tripping mechanism moved by the voltage tripping device 80 is shown in the recess below the slide cover 70 in this figure, and the voltage tripping device 80 has the operation pin 3P , The trip mechanism 5 is operated to cut off the circuit.

FIG. 3 shows the drive pin 3P and the tripping mechanism 5 which performs a trip operation by moving the operation pin 3P. The operation pin 3P is moved in the direction indicated by an arrow in FIG. By moving, the tripping mechanism 5 including the tripping lever 3A, the movable core 52, and the transmission lever 53 is operated to rotate the holding member 22 to move the movable contacts 13 and 15 from the fixed contacts 12 and 15. Break apart.
FIG. 3A shows the operation pin 3.
The state of the tripping mechanism 5 before the movement of P, and FIG.
(B) shows the state after the movement of the operation pin 3P.

FIG. 1 shows that the pulling mechanism 3P is pulled to move the position of the operating pin 3P so that the trip mechanism 5P is moved.
The voltage trip device 8 is a device for operating the
0 is shown. The voltage tripping device 80 incorporated in the molded case 6 which is an insulating casing of the circuit breaker has a yoke 100 constituting a magnetic path and a structure such as a caulking method. Fixed core 110 to be joined and fixed core 110
Movable core 120 slidably provided corresponding to
And an electromagnetic coil 130 for magnetically attracting and moving the movable core 120. Reference numeral 135 in the figure denotes a bobbin around which the electromagnetic coil 130 is wound. In the center of the bobbin 135, a groove in which the movable core 120 can slide is formed.

As shown in FIG. 1, the tip of the movable core 120 of the voltage trip device 80 is formed in a hook shape, and the hook portion 125 is connected to the operating pin 3P.
With a predetermined distance, ie, an air gap. Further, as is apparent from the drawing, a return spring 140 is engaged with the concave portion 126 formed in a part of the movable core 120, and thereby, the symbol F
A return force acts on the movable core 120 by the force indicated by 1. Reference numerals 141 and 142 in the figure denote a shaft member for attaching the return spring 140 to the voltage trip device 80 and a fixing portion thereof.

In the voltage trip device 80 having the above-described configuration, a magnetic force is generated in the electromagnetic coil 130 by an excitation current flowing in response to a signal from a distance, and the movable core 120 is attracted by the generated magnetic force. Then, it moves in the direction indicated by arrow P in the figure. And this movable core 12
0 moves over the predetermined air gap distance, and the hook-like portion 125 comes into contact with the operating pin 3P. Thereafter, the hook-shaped portion 125 is further attracted and moved by the magnetic force of the electromagnetic coil 130, thereby moving the operating pin 3P. Will be subtracted. At this time, the movable core 1 is moved by the return spring 140.
The force acting on the hook portions 125 of 20 is indicated by the symbol F2 in the figure.

As is apparent from FIG. 1, the attractive force P acting on the movable core 120 due to the magnetic force of the electromagnetic coil 130 acts on a substantially central portion of the movable core 120. The reaction force F1 of the return spring 140 that applies a return force to the movable core 120 acts in a direction opposite to the acting force P. Further, a symbol F2 is provided between a concave portion 126 formed in a part of the movable core 120 and a hook-like portion 125 which comes into contact with the operation pin 3P.
A reaction force acts on the position of the arrow shown by. Therefore, according to the present invention, the suction force P acting on the movable core 120 is:
A force F1 acting on the concave portion 126 and the hook-like portion 125 as the reaction force.
And F2.
More specifically, the respective positions of the suction force P acting on the movable core 120 are arranged such that the line of action of the suction force P is located substantially at an intermediate position of a straight line connecting the positions where the forces F1 and F2 act. Things.

According to the above arrangement,
Since the forces F1 and F2 balance and act equally on the suction force P, the electromagnetic coil can be surely prevented without generating a rotational moment or the like on the movable core 120 and causing a phenomenon such as a one-sided contact. The movable core 120 can be attracted by the magnetic force of 130. Therefore, it is possible to reliably perform a desired circuit shut-off operation by the opening / closing mechanism irrespective of the influence of aging or the like.

In the above description of the embodiment, in particular, as described above, the voltage trip device (SHT), which is an accessory device for electrically tripping the circuit breaker from a distance, is described in detail. explained. However,
The present invention is not limited to this. For example, the present invention is similarly applied to a device which is provided in the mold case 6 in advance to operate the tripping mechanism 5 when a short circuit or an overcurrent occurs. It is possible to It will be apparent to those skilled in the art that the same effect as described above can be achieved.

[0032]

As is apparent from the above detailed description, according to the circuit breaker and the voltage trip device according to the present invention, as is apparent from the structure, the circuit breaker is attracted by the generated electromagnetic force. The problem that the movable core that slides and slides does not achieve the desired suction operation due to a phenomenon such as a one-sided contact does not interfere with the circuit breaking operation, so that the contacts in the circuit breaker are surely made despite the aging. An extremely excellent effect of providing a highly reliable circuit breaker capable of operating the open / close mechanism of the present invention and a voltage trip device as an auxiliary device thereof can be achieved.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional perspective view showing a detailed internal structure of a voltage trip device of a circuit breaker according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a state where the voltage trip device shown in FIG. 1 is attached to a part of the circuit breaker of the present invention and stored.

FIG. 3 is an operation explanatory diagram for explaining a switching mechanism inside a circuit breaker operated by the voltage trip device shown in FIG. 1;

FIG. 4 is a sectional view showing an internal detailed structure of the circuit breaker.

FIG. 5 is a top view showing the overall appearance of the circuit breaker.

FIG. 6 is a perspective view showing the overall appearance of the circuit breaker.

FIG. 7 is an exploded perspective view illustrating the structure of three-phase moving contacts constituting a main circuit of the circuit breaker.

FIG. 8 is a perspective view showing a detailed structure of an opening / closing mechanism unit of the circuit breaker.

FIG. 9 is an exploded perspective view showing an internal detailed structure of a main circuit case of the circuit breaker.

10 is a top view showing a structure in which the main circuit cases of FIG. 9 are arranged in three phases in parallel.

[Explanation of symbols]

 3P operating pin 5 tripping mechanism 6 mold case 41 opening / closing operation handle 55 current transformer (CT) 6 mold case 61 bottom case 62 front cover 12 power-side fixed contact 13 power-side movable contact 15 load-side movable contact 16 load-side fixed contact Reference Signs List 80 voltage release device 100 yoke 110 fixed core 120 movable core 130 electromagnetic coil 125 hook portion 140 return spring

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Koichi Yokoyama 46-1 Tomioka, Nakajo-cho, Kitakanbara-gun, Niigata Industrial Machinery Division, Hitachi, Ltd. (72) Inventor Hidetaka Fujita 46 Tomioka, Nakajo-cho, Kitakanbara-gun, Niigata Prefecture Address 1 Within the Industrial Equipment Division, Hitachi, Ltd. (56) References JP-A-63-184229 (JP, A) JP 6-2189 (JP, Y2)

Claims (4)

(57) [Claims] 1. An electric circuit opening / closing operation by an operation handle operates a mechanism housed in an insulating case to open and close at least a pair of contacts housed in the insulating case, and an overcurrent exceeding a rated current. A circuit breaker that detects the contact point and disconnects the pair of contacts by the mechanism unit, and further includes, in the insulating case, an operating unit for operating the mechanism unit; An electromagnetic actuating means for moving the actuating part to operate, wherein the electromagnetic actuating means is provided with a movable core slidably inside a yoke part and an electromagnetic coil provided in the yoke part; the spring return part directly with preparative <br/> Ri put the core, the contact portion between the actuation portion is formed in a part, and working attracting force exerted by the electromagnetic force against the movable core position , The suction force at the movable core
Is arranged so as to act at a substantially intermediate position between a position where the return force of the return spring acts and a position where the reaction force from the operating portion acts in a direction perpendicular to the direction in which the force acts. A circuit breaker, characterized in that: 2. A circuit breaker as set forth in claim 1, further wherein the suction force, the return to the return force of the spring and acts in the opposite direction, against the movable core
The attraction force exerted by the electromagnetic force is substantially on a line connecting the position where the return spring abuts against the movable core to apply the return force and the position where the return spring abuts on the operating portion and the reaction force is applied. A circuit breaker, wherein the circuit breaker is arranged to operate at an intermediate position. 3. An opening / closing operation of an electric circuit by an operation handle operates a mechanical unit housed in an insulating case to open and close at least a pair of contacts housed in the insulating case, and an overcurrent exceeding a rated current. A part of the circuit breaker that detects and disconnects the pair of contacts by the mechanism unit.
Are store, a voltage trip device for a circuit is cut off by operating the remotely by driving the operating portion of the mechanism section disposed in the insulating casing of the circuit breaker, and the yoke portion, wherein A movable core is slidably provided inside an electromagnetic coil provided in the yoke part, and a return spring is directly attached to a part of the movable core, and a contact part with the operating part is formed in a part thereof, and attracting force exerted by the electromagnetic force against the movable core, those the suction in the movable core
In a direction perpendicular to the direction in which the force acts, it is disposed so as to act at a substantially intermediate position between the position where the return force of the return spring acts and the position where the reaction force from the operating portion acts. A circuit trip device for tripping a voltage. 4. The voltage trip device for a circuit breaker according to claim 3, wherein the suction force acts in a direction opposite to a return force of the return spring,
Attracting force exerted by the electromagnetic force against the movable core, and a position where the return spring against the movable core exerts a return force in contact, and a position in which the actuating portion and the contact with the reaction force acts A device for tripping a voltage of a circuit breaker, wherein the device is arranged to operate at a substantially intermediate position on a connecting line.